The Secretary of State may, if it appears to him to be necessary or expedient so to do, by order suspend or relax the operation of section 20 (prohibition of smoke emissions in smoke control area) in relation to the whole or any part of a smoke control area.

Before making an order under subsection (1) the Secretary of State shall consult with the local authority unless he is satisfied that, on account of urgency, such consultation is impracticable.

As soon as practicable after the making of such an order the local authority shall take such steps as appear to them suitable for bringing the effect of the order to the notice of persons affected.